基于DataStream实战

案例演示：基于DataStream实现Flink CDC从MySQL数据库flink_db.tb_product表实时捕获增量数据，并打印在控制台。

添加Maven依赖：

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<dependency>
    <groupId>com.ververica</groupId>
    <artifactId>flink-connector-mysql-cdc</artifactId>
    <version>2.3.0</version>
</dependency>

编码实现：

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package com.itbaizhan.flink.java.cdc;

import com.ververica.cdc.connectors.mysql.source.MySqlSource;
import com.ververica.cdc.connectors.mysql.table.StartupOptions;
import com.ververica.cdc.debezium.JsonDebeziumDeserializationSchema;
import org.apache.flink.api.common.eventtime.WatermarkStrategy;
import org.apache.flink.streaming.api.CheckpointingMode;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;

public class CdcMySQLDataStreamDemo {
    public static void main(String[] args) throws Exception {
        //1.构建MySqlSource对象
        MySqlSource<String> mySqlSource = MySqlSource.<String>builder()
                .hostname("192.168.20.101")
                .port(3306)
                .databaseList("flink_db") // set captured database
                .tableList("flink_db.tb_product") // set captured table
                .username("root")
                .password("123456")
                /**initial():首次启动时对监控的数据先全量，后增量
                 * earliest():只是从二进制binlog的开头读取。
                 * latest():只是从二进制binlog的结尾读取。
                 */
                .startupOptions(StartupOptions.initial())
                // converts SourceRecord to JSON String
                .deserializer(new JsonDebeziumDeserializationSchema())
                .build();
       //2.构建执行环境对象
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        //设置checkpoint
        env.enableCheckpointing(1000, CheckpointingMode.AT_LEAST_ONCE);
        env.getCheckpointConfig().setCheckpointStorage("file:///E:/flink_checkpoint1");
        //3.添加数据源
        DataStreamSource<String> dataStreamSource = env.fromSource(mySqlSource, WatermarkStrategy.noWatermarks(), "MySQL Source");
        //...转换...
        //4.输出
        dataStreamSource.printToErr().setParallelism(1);
        //5.执行
        env.execute("CdcMySQLDataStreamDemo");
    }
}

Bug解决办法：

首先依赖调整

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<!--<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.7</version>
    <scope>runtime</scope>
</dependency>-->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.25</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.25</version>
</dependency>

然后将软件\log4j2.xml拷贝到当前项目的resources目录下。

INSERT INTO tb_product(id,NAME,price) VALUES(9,'macbook1',9999);

INSERT INTO tb_product(id,NAME,price) VALUES(10,'macbook2',8888);